Comparison of alkali and steam (acid) pretreatments of lignocellulosic materials to increase enzymic susceptibility: Evaluation under optimised pretreatment conditions

The alkali pretreatment of sugar cane bagasse was optimised and compared with an optimised steam (acid) pretreatment. The optimised alkali pretreatment gave an overall sugar yield of 37.4 g sugars per 100 g bagasse accounting for 43.8% of the initial xylan and 64.5% of the glucan. Potential effluent problems were identified with the alkali treatment and several strategies were suggested to minimise them, with liquor recycling showing some promise. The optimised steam (acid) pretreatment gave an overall sugar yield of 55.7 g sugars per 100 g bagasse accounting for 76.5% of the xylan and 89.5% of the glucan. The superiority of the steam (acid) pretreatment over the alkali pretreatment depends on the ability to utilise the xylose produced.     

A small supernumerary metacentric chromosome: interprétation test (author's transl)]

The report relates to a new case of small supernumerary metacentric chromosome. The phenotypical variability of previously published cases suggests that this chromosomal anomaly may arise from multiple origins. Our study shows the difficulties of a cytogenetic interpretation and the limits of the semeiologic arguments. It is, however, possible to hypothesize an 18 partial trisomy.     

Regional interfuel substitution by electric companies: The short-term prospects

This paper uses a translog price possibility frontier to measure the extent of regional interfuel substitution effects in the electric utility industry in the United States. Monthly data based on Department of Energy regions serve as the vehicle around which the estimation is performed. Given the nonlinear character of the price possibility frontier specification, an iterative Zellner seemingly unrelated regression technique is used for estimating the parameters of the model. The results suggest that relative changes in fuel prices have significant effects on fossil fuel consumption. This, in turn, has important implications for public policy. In particular, the market system appears better able to deal with exogenous shifts in energy supplies than has frequently been assumed in the formulation of energy policy toward the energy crisis.The author is an economist with the Department of Energy, Office of Conservation and Solar Applications. The views expressed are those of the author and do not necessarily represent the policies of the Department of Energy or the views of other Department of Energy staff members.     

Models for estimating undiscovered oil resources

This paper is directed at estimating total producible oil in the United States. Two specific models are suggested and estimated in a fashion consistent with the theoretical considerations. The results suggest that approximately 159 billion barrels are ultimately recoverable and producible, of which 114 billion barrels had been produced by the end of 1977.     

Morphology of polyethylene-polypropylene blends

The morphology of blends of high-density polyethylene (PE) and isotactic polypropylene (PP) was studied by mesans of optical and scanning-electron microscopy. In the range of 10 to 90 percent by weight PE, these blends are two-phase systems, the components of which crystallize separately into discrete phases. The presence of PE has a definite and pronounced effect on the crystalline structure of the PP, whose spherulitic structure becomes increasingly irregular and coarse with increasing PE content. The light transmission of these blends during melting and crystallization was also studied in an attempt to characterize them.     

Polymers with mesogenic elements and flexible spacers in the main chain: Aromatic-aliphatic polyesters

A new series of aromatic-aliphatic polyesters of general structure: R₁ = terphenyl, biphenyl, stilbene R₂ = (CH₂)_n; ? CH₂? C(Me)₂? CH₂? ;? CH₂;? C(Et)₂? CH₂? ; (CH₂? CH₂? O)_n CH₂? CH₂? has been synthesised. The existence of thermotrpic liquid crystalline phases has been shown by polarised light microscopy. The texture observations have suggested the existence of nematic, S_A or/and S_C phases depending on the chemical structure. The temperature of transition between the phases and, as a consequence, the range of mesomorphism are highly dependent upon the chemical structure. The clearing point is high, even for the longest aliphatic group, while the melting point is depressed.     

Process-data-warehousing-based operator support system for complex production technologies

Process manufacturing is increasingly being driven by market forces, customer needs, and perceptions, resulting in more and more complex multiproduct manufacturing technologies. The increasing automation and tighter quality constraints related to these processes make the operator's job more and more difficult. This makes decision support systems (DSSs) for the operator more important than ever before. A traditional operator support system (OSS) focuses only on specific tasks that are performed. In the case of complex processes, the design of an integrated information system is extremely important. The proposed data-warehouse-based OSS makes possible linking complex and isolated production units based on the integration of the heterogenous information collected from the production units of a complex production process. The developed OSS is based on a data warehouse designed by following the proposed focus-on-process data-warehouse-design approach, which means stronger focus on the material and information flow through the entire enterprise. The resulting OSS follows the process through the organization instead of focusing separate tasks of the isolated process units. For human-computer interaction, front-end tools have been worked out, where exploratory data analysis and advanced multivariate statistical models are applied to extract the most informative features of the operation of the technology. The concept is illustrated by an industrial case study, where the OSS is designed for the monitoring and control of a high-density polyethylene (HDPE) plant.     

Active‐matrix organic light‐emitting displays employing two thin‐film‐transistor a‐Si:H pixels on flexible stainless‐steel foil

Abstract— An active‐matrix organic light‐emitting diode (AMOLED) display driven by hydrogenated amorphous‐silicon thin‐film transistors (a‐Si:H TFTs) on flexible, stainless‐steel foil was demonstrated. The 2‐TFT voltage‐programmed pixel circuits were fabricated using a standard a‐Si:H process at maximum temperature of 280°C in a bottom‐gate staggered source‐drain geometry. The 70‐ppi monochrome display consists of (48 × 4) × 48 subpixels of 92 ×369 μm each, with an aperture ratio of 48%. The a‐Si:H TFT pixel circuits drive top‐emitting green electrophosphorescent OLEDs to a peak luminance of 2000 cd/m².     

图像导引介入治疗中可视化3D的2D/3D图像数据分析

三维成像对许多医学过程(根本上是对患者的健康)来说,是非常关键的。本文探讨了三维成像方法的与众不同之处,以及作为一种不断发展创新的技术,临床医生们对它的需求和期待。